I apologize if this has been answered elsewhere, but I couldn't find anything on a search.
I was looking at some NBA regular season win total over/unders. For example, here is Chicago:
Over 41 (-125)
Under 41 (-105)
Since -125 doesn't match -105, is there a way to calculate the number of wins the Bookmaker actually expects - it seems like it can't really be exactly 41.
Normalize it to remove the juice and then put it into a poisson-based season-wins estimate. The vig-free line there is approximately ov41 -109/un41 +109, which poisson tells us is about the same as 41.23 wins.